Characteristics of p-hydroxybenzoic acid oxidation using Fenton's reagent.

The objective of this work was to investigate the oxidation of p-hydroxybenzoic acid by the Fenton's reagent. Batch experiments were carried out to investigate the influence of the most important process variables: hydrogen peroxide and ferrous salt concentrations, pH, and temperature. The optimal results obtained indicate that p-hydroxybenzoic acid can be effectively degraded using Fenton's oxidation within 10-min reaction time by using a molar ratio H2O2: p-hydroxybenzoic acid of 4:1 and H2O2:Fe2+ of 15:1, at 30 degrees C and pH=3.0. The behavior of ORP and pH along the reaction time for different values of R (molar ratio H2O2: p-hydroxybenzoic acid) was also discussed. A pseudo-first order model was applied to describe the oxidation kinetics of p-hydroxybenzoic acid by Fenton's reagent.